Weld electrical and gas connector with sealed gas flow

ABSTRACT

A welding cable connector system having a male connector and a female connector. The male connector includes a first conductive body for conveying welding power. The male connector also includes a first sealed passageway disposed coaxially of the first conductive body for conveying shielding gas, and a first Schrader valve configured to stop flow of shielding gas when the male connector is not engaged. The female connector includes a second conductive body for conveying welding power. The female connector also includes a second sealed passageway disposed coaxially of the conductive body for conveying shielding gas, and a second Schrader valve configured to stop flow of shielding gas when the female connector is not engaged. The male and female connectors are mutually engageable to conduct welding power and shielding gas therethrough. The first and second Schrader valves seal the flow of shielding gas when the connectors are not mutually engaged.

BACKGROUND

The invention relates generally to welding systems and, moreparticularly, to a weld electrical and gas connector with sealed gasflow.

Welding is a process that has become increasingly ubiquitous in variousindustries and applications. While such processes may be automated incertain contexts, a large number of applications continue to exist formanual welding operations. Such welding operations rely on a variety oftypes of equipment to ensure the supply of welding consumables (e.g.,wire feed, shielding gas, etc.) is provided to the weld in anappropriate amount at the desired time. For example, metal inert gas(MIG) welding typically relies on a wire feeder to ensure a proper wirefeed reaches a welding torch, as well as gas-channeling tubes or cablesfor routing shielding gas to the torch during the time a welding arc iscreated between the wire and a workpiece.

Welding power sources used in such applications are designed to providepower for welding, while wire feeders are used to deliver welding wireto a welding torch. Shielding gas may be provided to the power supply,and therefrom to the wire feeder, where a weld cable routes the wire,gas, and power to the torch. Cables connect welding power sources towire feeders and wire feeders to welding torches. Other weldingequipment is also connected using cables. Some welding systems utilizecable bundles to capture the quantity of cables that may be used toconnect welding equipment. For example, a welding system may include upto three separate cables for connecting between any two welding devices,a cable for each of power, gas, and data. As such, certain cableassemblies may be constructed to transport welding power and shieldinggas in a single cable. Unfortunately, such cable assemblies may includea large number of components and may be complicated to construct.Accordingly, there exists a need for welding cable assemblies thatovercome such disadvantages.

BRIEF DESCRIPTION

In one embodiment, a welding cable connector system includes a maleconnector having a first conductive body for conveying welding power.The male connector includes a first sealed passageway disposed coaxiallyof the first conductive body for conveying shielding gas, and a firstSchrader valve configured to stop flow of shielding gas when the maleconnector is not engaged. The cable connector system also includes afemale connector having a second conductive body for conveying weldingpower. The female connector includes a second sealed passageway disposedcoaxially of the conductive body for conveying shielding gas, and asecond Schrader valve configured to stop flow of shielding gas when thefemale connector is not engaged. The male and female connectors aremutually engageable to conduct welding power and shielding gastherethrough. The first and second Schrader valves seal the flow ofshielding gas when the connectors are not mutually engaged.

In another embodiment, a welding cable connector system includes aconnector having a conductive body for conveying welding power to orfrom a mating connector. The connector system also includes a sealedpassageway disposed coaxially of the conductive body for conveyingshielding gas to or from the mating connector. The sealed passagewayincludes threads configured to engage a preassembled valve assembly.

In another embodiment, a welding cable connector system includes a maleconnector having a first conductive body for conveying welding power.The male connector also includes a first sealed passageway disposedcoaxially of the first conductive body for conveying shielding gas, anda first preassembled valve assembly coupled to threads within the firstsealed passageway and configured to stop flow of shielding gas when themale connector is not engaged. The connector system also includes afemale connector having a second conductive body for conveying weldingpower. The female connector also includes a second sealed passagewaydisposed coaxially of the conductive body for conveying shielding gas,and a second preassembled valve assembly coupled to threads within thesecond sealed passageway and configured to stop flow of shielding gaswhen the female connector is not engaged. The connector system includesa welding cable coupled to at least one of the male and femaleconnectors for conveying welding power and shielding gas to or from thecoupled connector. The male and female connectors are mutuallyengageable to conduct welding power and shielding gas therethrough. Thefirst and second preassembled valve assemblies seal the flow ofshielding gas when the connectors are not mutually engaged.

DRAWINGS

These and other features, aspects, and advantages of the presentinvention will become better understood when the following detaileddescription is read with reference to the accompanying drawings in whichlike characters represent like parts throughout the drawings, wherein:

FIG. 1 is a schematic diagram of an exemplary welding system inaccordance with aspects of the present disclosure;

FIG. 2 is a schematic diagram of an exemplary welding system including apendant in accordance with aspects of the present disclosure;

FIG. 3 is a perspective view of an embodiment of a welding cableassembly;

FIG. 4 is an exploded view of an embodiment of a male connector assemblyof a welding cable assembly;

FIG. 5 is an exploded view of an embodiment of a female connectorassembly of a welding cable assembly;

FIG. 6 is a cross-sectional side view of an embodiment of male andfemale connector assemblies of a welding cable assembly; and

FIG. 7 is a cross-sectional side view of the embodiment of FIG. 6 withthe male and female connector assemblies mated.

DETAILED DESCRIPTION

As described in detail below, embodiments of a weld electrical and gasconnector with sealed gas flow are provided that may facilitate fewercomponents and simplified construction. For example, in certainembodiments a Schrader valve is used to control the flow of gas throughthe connectors, while in other embodiments a preassembled valve assemblyis used to control the flow of gas through the connectors. In eithercase, the connectors are manufactured in a simplified manner using fewercomponents.

Turning now to the figures, FIG. 1 is a schematic diagram of anexemplary welding system 10 which powers, controls, and providessupplies to a welding operation. The welding system 10 includes awelding power supply 12, a wire feeder 14, a torch 16, and a workpiece18. The welding power supply 12 receives primary power 20 (e.g., fromthe AC power grid, an engine/generator set, a battery, or a combinationthereof), conditions the input power, and provides an output power toone or more welding devices in accordance with demands of the system 10.The primary power 20 may be supplied from an offsite location (i.e., theprimary power may originate from a wall outlet). The welding powersource 12 includes power conversion circuitry 22 that may includecircuit elements such as transformers, rectifiers, switches, and soforth, capable of converting the AC input power to a DCEP or DCEN outputas dictated by the demands of the system 10. Such circuits are generallyknown in the art. It should be noted, however, that the cable structuresdisclosed herein may be used with any desired welding application orprocess that relies on the provision of power and shielding gas. Thismight include, for example, AC welding processes, DC welding processes,pulsed and short circuit welding processes, hybrid processes, and soforth. Moreover, the cabling may be used for such processes and maychannel power and gas when needed, but may still be used when otherprocesses are employed that do not require shielding gas. When this typeof process is selected, the flow of gas through the cable is simplystopped by system valving of a conventional type.

In some embodiments, the power conversion circuitry 22 may be configuredto convert the primary power to both weld and auxiliary power outputs.However, in other embodiments, the power conversion circuitry 22 may beadapted to convert primary power only to a weld power output, and aseparate auxiliary converter may be provided to convert primary power toauxiliary power. Still further, in some embodiments, the welding powersupply 12 may be adapted to receive a converted auxiliary power outputdirectly from a wall outlet. Indeed, any suitable power conversionsystem or mechanism may be employed by the welding power supply 12 togenerate and supply both weld and auxiliary power.

The welding power supply 12 includes a user interface 26 and controlcircuitry 28. The control circuitry 28 controls the operations of thewelding power supply 12 and may receive input from the user interface 26through which a user may choose a process, and input desired parameters(e.g., voltages, currents, particular pulsed or non-pulsed weldingregimes, and so forth). The control circuitry 28 may also be configuredto receive and process a plurality of inputs regarding the performanceand demands of the system 10. Furthermore, the control circuitry 28 mayinclude volatile or non-volatile memory, such as ROM, RAM, magneticstorage memory, optical storage memory, or a combination thereof. Inaddition, a variety of control parameters may be stored in the memoryalong with code configured to provide a specific output (e.g., initiatewire feed, enable gas flow, etc.) during operation.

The welding power supply 12 may also include a valve 30 to modulate theamount of gas supplied to a welding operation. The valve 30 operateswith signals from the control circuitry 28. A gas supply 34 may provideshielding gases, such as argon, helium, carbon dioxide, and so forth.The gas enters valve 30 then exits the valve through cable 36. Asillustrated, the gas and power are combined into the cable 36. As such,the cable 36 supplies the wire feeder 14 and/or torch 16 with gas andpower. The cable 36 is coupled to connector 38. The connector 38 is afemale box mount connector that is mounted to the welding power supply12. In certain embodiments, the connector 38 may be a male box mountconnector, or the connector 38 may be any connector that can combine gasand power connections therethrough.

Data is communicated between the control circuitry 28 and an interfacecircuit 40. The interface circuit 40 conditions the data from thecontrol circuitry 28 for communication to other welding devices, such asa wire feeder 14 and a pendant. The interface circuit 40 may beconnected to connector 38 for transmission of data combined with thepower and gas. In another embodiment, data conditioned in the weldingpower supply 12 is communicated to the wire feeder 14 over a controlcable assembly 44. Certain power signals may also be transmitted overthe control cable assembly 44.

A cable assembly 46 connects the welding power supply 12 to the wirefeeder 14. A male connector assembly 48 is coupled to connector 38 onthe power supply 12 and a female connector assembly 50 is coupled to amale box mount connector 52 on the wire feeder 14. In certainembodiments, the connector 52 may be a female box mounted connector, orconnector 52 may be another type of connector. Furthermore, in otherembodiments, the connector assemblies 48 and 50 may be male or femaleassemblies such that connector assemblies 48 and 50 mate with connectors38 and 52 respectively. The cable assembly 46 includes a cable 54coupled to connector assemblies 48 and 50. In addition, the cableassembly 46 may include multiple cables, such that the assembly mayinclude connector assemblies 56 and 58. Likewise, one, two or morecables may be part of the assembly 46. The workpiece 18 is also coupledto the welding power supply 12 to provide a return path for weldingpower.

Gas and power run between the connector 52 and a female box mountconnector 60. Again, the connector 60 may be a male box mount connector,or any other connector that can carry gas and power. A power conversioncircuitry 62 is powered from the gas/power cable. The wire feeder 14also includes a user interface 66 and control circuitry 68. The powerconversion circuitry 62 powers the control circuitry 68. The controlcircuitry 68 functions similar to control circuitry 28, but controls thefunctionality of the wire feeder 14. The control circuitry 68 mayreceive input from the user interface 66 through which a user may inputdesired parameters (e.g., voltages, currents, wire speed, and so forth).Further, an interface circuit 70 may receive signals from controlcircuitry 68 for transmission to the welding power supply 12.Conditioned data is received by the wire feeder 14 and converted by theinterface circuit 70 to signals compatible with the control circuitry68. The interface circuit 70 may receive conditioned data either throughcable 44, or through cable assembly 46 as illustrated. The wire feeder14 also includes a wire drive 74 that receives control signals from thecontrol circuit 68 to drive rollers 75 that cause wire to be fed from awire spool 76. Gas and power are transferred out of the wire feeder 14through connector 60. A male connector assembly 78 coupled to a cable 80enable the gas and power to be provided to the torch 16 for a weldingoperation. In certain embodiments, the connector assembly 78 may be afemale connector assembly. It should be noted that the gas flowingthrough the cable assembly 46, or the cable 80 may have a cooling effecton the cable. Further, each of the connector assemblies described abovemay be constructed using a Schrader valve, or another preassembled valveassembly.

FIG. 2 is a schematic diagram of an exemplary welding system 10including a pendant 82. The welding power supply 12, wire feeder 14, andtorch 16 function in a similar manner as described in relation toFIG. 1. As illustrated, a second cable assembly 46 connects betweenconnector 60 of the wire feeder 14 and a male box connector 84 of thependant 82. As previously described, gas and power are carried by cableassembly 46. The gas and power exit the pendant 82 through a female boxconnector 86 to provide gas and power to the torch 16. In certainembodiments, connectors 84 and 86 may be either male or female and maybe any type of connector that can carry gas and power. The pendant 82also includes power conversion circuitry 88, a user interface 92,control circuitry 94, and an interface circuit 96. The circuits andinterfaces of the pendant 82 function in a similar manner to thesimilarly named circuits and interfaces previously described, thuscontrolling the operation of the pendant. A second control cableassembly 44 communicates control data and/or power between the wirefeeder 14 and the pendant 82. The interface circuit 96 may eitherreceive data via cable assembly 44 or via connection 98 from the gas andpower cable. As may be appreciated, each of the connector assembliesdescribed above may be constructed using a Schrader valve, or anotherpreassembled valve assembly.

FIG. 3 is a perspective view of an embodiment of a welding cableassembly 46. The male connector assembly 48 and female connectorassembly 50 are connected via a cable 54. The male connector assembly 48includes a collar 100 and a collar extension 102 that encompasses a maleconnector 104. The male connector 104 includes keyed threads 106 and afitting 108. The fitting 108 houses the gas valve which includes aplunger 110 portion of a preassembled valve assembly (e.g., Schradervalve, tire valve, etc.) extending out of the fitting 108. A collar keynotch 112 enables proper mating between male and female connectorassemblies. A spring 114 is disposed around the cable 54 adjacent to thecollar 100. The spring 114 may be part of a strain relief assembly. Thestrain relief assembly may also include a spring retainer (not shown) tohold the spring 114 in place. Further, the spring 114 may be doublepitched to enable the spring to mate with the spring retainer. Forexample, the spring 114 may include coils, such as approximately 10coils, with a pitch such as approximately 0.16 inches to enable thespring 114 to be threaded onto the spring retainer. The remainder of thethreads may be pitched at approximately 0.625 inches to enable a largeradius bend. In addition, the spring retainer may be captured within thecollar 100 to hold the retainer and spring 114 behind the collar 100.

The female connector assembly 50 also includes the collar 100 and acollar extension 116 that encompasses a female connector 118. The femaleconnector 118 includes keyed threads 120 and a tapered surface 122. Thetapered surface 122 contacts a tapered surface of the male connector 104in order to conduct electric current between the male and femaleconnectors. Further, the tapered surface 122 may engage the maleconnector 104 such that the surface maintains a tight engagement with amating connector. In addition, the tapered surface 122 may initiatecleaning action to enable increased electrical conductivity. A collarkey 124 enables proper mating between male and female connectorassemblies. The female connector assembly 50 also includes the spring114 and may include a strain relief assembly as described above.

As may be appreciated, the spring 114 on the male or female connectorassemblies 48 and 50 may be configured different than described above.For example, in certain embodiments the spring 114 may have only asingle pitch, or the spring 114 may be double pitched with a first setof coils (which may be greater or less than 10 coils) having a pitchless than or greater than approximately 0.16 inches and the remainder ofthe coils having a pitch less than or greater than approximately 0.625inches. The collar 100 and the collar extensions 102 and 116 may inhibitthe connectors 104 and 118 from contacting other surfaces. As such, theconnectors 104 and 118 may be inhibited from inadvertent electricalcontact with an undesired surface. Further, the connectors 104 and 118may be protected from physical impact with other surfaces.

FIG. 4 is an exploded view of an embodiment of a male connector assembly48 of a welding cable assembly. The male connector assembly 48 includesthe collar 100 with two sections that are assembled on the outside ofthe male connector 104, such as via screws. The collar extension 102 ismounted over the front of the male connector 104. The collar 100 and thecollar extension 102 may be made of plastic, rubber, polymer, or othermaterial that provides protection to the male connector 104. The maleconnector 104 includes the keyed threads 106 and the fitting 108. Thekeyed threads 106 are keyed to mate with the keyed threads of the femaleconnector 118 via a ¼ turn twist-lock in order to hold the male andfemale connectors engaged. The threads of the male and female connectorsmay be keyed per U.S. Pat. No. 7,377,825, entitled “High-powerElectrical Quick Connector” to Bankstahl, which is hereby incorporatedby reference. The male connector 104 also includes a tapered surface 126and a nut 128. The tapered surface 126 is tapered to match the taper onthe female connector 118. The tapered surfaces of the male and femaleconnectors contact each other to provide a conductive pathway forwelding power to flow. The tapered surface 126 may include any degree oftaper such that the angle provides a good contact between theconnectors. For example, the taper may be approximately 100, 110, 115,or 135 degrees. The nut 128 is used to tighten a cable adaptor onto themale connector 104. The male connector 104 may be made of brass, nickel,stainless steel, or another conductive material sufficient to conductpower and carry gas.

The plunger 110 (or extension) is part of a preassembled valve assembly134. In certain embodiments, the preassembled valve assembly 134 may bea Schrader valve, a tire valve, a tyre valve, an American valve, oranother type of preassembled valve assembly. Further, the preassembledvalve assembly 134 may include 5V1 size threading and may be one of manydifferent grades (e.g., tire grade, aircraft grade, etc.). The plunger110 extends out of the preassembled valve assembly 134. The preassembledvalve assembly 134 includes threads 136 which threadingly engagedmatching threads within a passageway of the male connector 104. Thus,gas is inhibited from flowing through the male connector 104 when thepreassembled valve assembly 134 is properly installed and not engagedwith another valve assembly, forming a sealed passageway within the maleconnector 104. As will be appreciated, the preassembled valve assembly134 is mechanically unseated and allows gas to flow through the maleconnector 104 upon mating of the male connector 104. An adaptor 146 issecured to the male connector 104 and enables the connector 104 to beattached to a welding cable, such as a ¼ inch pipe thread crimped to aweld cable of a type commercially available from Bernard of Beecher,Ill. Using the preassembled valve assembly 134, the male connectorassembly 48 is manufactured in a more efficient and simplified mannerusing fewer components.

FIG. 5 is an exploded view of an embodiment of a female connectorassembly 50 of a welding cable assembly. The female connector assembly50 includes the collar 100 with two sections that are assembled on theoutside of the female connector 118, such as via screws. The collarextension 116 is mounted over the front of the female connector 118. Thecollar 100 and collar extension 116 may be made of plastic, rubber,polymer, or other material that provides protection to the femaleconnector 118. The female connector 118 also includes a nut 148. The nut148 fits within the similar shaped interior of the collar extension 116.The female connector 118 may be made of brass, nickel, stainless steel,or another conductive material sufficient to conduct power and carrygas.

A preassembled valve assembly 156 includes a plunger 158 (or extension).In certain embodiments, the preassembled valve assembly 156 may be aSchrader valve, a tire valve, a tyre valve, an American valve, oranother type of preassembled valve assembly. Further, the preassembledvalve assembly 156 may include 5V1 size threading and may be one of manydifferent grades (e.g., tire grade, aircraft grade, etc.). The plunger158 extends out of the preassembled valve assembly 156. The preassembledvalve assembly 156 includes threads 160 which threadingly engagematching threads within the female connector 118. Thus, gas is inhibitedfrom flowing through the female connector 118 when the preassembledvalve assembly 156 is properly installed and not engaged with anothervalve assembly, forming a sealed passageway within the female connector118. As will be appreciated, the preassembled valve assembly 156 ismechanically unseated and allows gas to flow through the femaleconnector 118 upon mating of the female connector 118. An adaptor 172 issecured to the female connector 118 and enables the connector 118 to beattached to a welding cable, such as a ¼ inch weld cable of a typecommercially available from Bernard of Beecher, Ill. Using thepreassembled valve assembly 156, the female connector assembly 50 ismanufactured in a more efficient and simplified manner using fewercomponents.

FIG. 6 is a cross-sectional side view of an embodiment of male andfemale connector assemblies of a welding cable assembly. Theillustration of the male connector assembly 48 depicts the plunger 110of the preassembled valve assembly 134 extending out of the fitting 108.The preassembled valve assembly 134 is threadingly engaged with the maleconnector 104. The preassembled valve assembly 134 creates a seal toinhibit gas from escaping through the fitting 108. When the plunger 110is depressed, the seal is opened and gas can flow through the maleconnector 104. For example, when the male connector 104 is mated withthe female connector 118, the plungers 110 and 158 press against eachother to unseat the valve assembly seals and enable gas to flow througheach connector. Further, as illustrated within the female connector 50,o-rings 160 and 162 provide a seal around the fitting 108 when thefitting is inserted through the o-rings. By using two o-rings, theo-rings 160 and 162 may create a double seal, or one o-ring 160 may actas a wiper to clean dirt or debris off of the fitting 108, while theother o-ring 162 creates a seal. The keyed threads 120 and 106 are alsodepicted, illustrating how the male and female connectors are coupledtogether.

FIG. 7 is a cross-sectional side view of the embodiment of FIG. 6 withthe male and female connector assemblies mated. As illustrated, theplunger 110 presses against the plunger 154 to enable gas to flowbetween the connectors. Further, the threads 106 are coupled to thethreads 120 and the fitting 108 is positioned within o-rings 160 and162. The tapered surfaces 126 and 122 contact each other to enable powerto be conducted between the connectors.

While only certain features of the invention have been illustrated anddescribed herein, many modifications and changes will occur to thoseskilled in the art. It is, therefore, to be understood that the appendedclaims are intended to cover all such modifications and changes as fallwithin the true spirit of the invention.

1. A welding cable connector system comprising: a male connectorcomprising a first conductive body for conveying welding power, a firstsealed passageway disposed coaxially of the first conductive body forconveying shielding gas, and a first Schrader valve configured to stopflow of shielding gas when the male connector is not engaged; and afemale connector comprising a second conductive body for conveyingwelding power, a second sealed passageway disposed coaxially of theconductive body for conveying shielding gas, and a second Schrader valveconfigured to stop flow of shielding gas when the female connector isnot engaged; wherein the male and female connectors are mutuallyengageable to conduct welding power and shielding gas therethrough, andwherein the first and second Schrader valves seal the flow of shieldinggas when the connectors are not mutually engaged.
 2. The system of claim1, wherein the first Schrader valve is threadingly attached to the firstsealed passageway and the second Schrader valve is threadingly attachedto the second sealed passageway.
 3. The system of claim 2, whereinthreads of the first and second Schrader valves comprise 5V1 threads. 4.The system of claim 1, wherein at least one of the male and femaleconnectors comprises an adapter for coupling the connector to a weldingcable.
 5. The system of claim 1, wherein the male and female connectorsare configured to mate by a twist-lock structure to mechanically holdthe male and female connectors engaged.
 6. The system of claim 1,wherein each of the first and second Schrader valves is mechanicallyunseated upon mating of the male and female connectors.
 7. The system ofclaim 6, wherein each of the first and second Schrader valves comprisesan extension that is mechanically contacted to unseat the respectiveSchrader valve upon mating of the male and female connectors.
 8. Thesystem of claim 6, wherein the male connector is configured to seal tothe female connector via a tapered seating surface.
 9. A welding cableconnector system comprising: a connector comprising a conductive bodyfor conveying welding power to or from a mating connector, and a sealedpassageway disposed coaxially of the conductive body for conveyingshielding gas to or from the mating connector, the sealed passagewaycomprising threads configured to engage a preassembled valve assembly.10. The system of claim 9, comprising the preassembled valve assemblycoupled to the sealed passageway threads and configured to stop flow ofshielding gas when the connector is not engaged with the matingconnector.
 11. The system of claim 10, wherein the preassembled valveassembly is mechanically unseated upon mating of the connector.
 12. Thesystem of claim 10, wherein the preassembled valve assembly comprises aSchrader valve.
 13. The system of claim 9, wherein the connector isconfigured to seal to the mating connector via a tapered seatingsurface.
 14. The system of claim 9, wherein the connector comprises atapered extension that is at least partially covered and protected by acollar extension.
 15. The system of claim 9, wherein the connectorcomprises a tapered seating surface to enable electrical conductivitywith the mating connector.
 16. A welding cable connector systemcomprising: a male connector comprising a first conductive body forconveying welding power, a first sealed passageway disposed coaxially ofthe first conductive body for conveying shielding gas, and a firstpreassembled valve assembly coupled to threads within the first sealedpassageway and configured to stop flow of shielding gas when the maleconnector is not engaged; a female connector comprising a secondconductive body for conveying welding power, a second sealed passagewaydisposed coaxially of the conductive body for conveying shielding gas,and a second preassembled valve assembly coupled to threads within thesecond sealed passageway and configured to stop flow of shielding gaswhen the female connector is not engaged; and a welding cable coupled toat least one of the male and female connectors for conveying weldingpower and shielding gas to or from the coupled connector; wherein themale and female connectors are mutually engageable to conduct weldingpower and shielding gas therethrough, and wherein the first and secondpreassembled valve assemblies seal the flow of shielding gas when theconnectors are not mutually engaged.
 17. The system of claim 16, whereinthe welding cable is coupled to the male connector at one end thereofand to the female connector at an opposite end thereof.
 18. The systemof claim 16, wherein each of the first and second preassembled valveassemblies is mechanically unseated upon mating of the male and femaleconnectors.
 19. The system of claim 16, wherein each of the first andsecond preassembled valve assemblies comprises a Schrader valve.
 20. Thesystem of claim 16, comprising a first spring assembly disposed aroundthe welding cable adjacent to the male connector and a second springassembly disposed around the welding cable adjacent to the femaleconnector.